#include "dns.h"
#include "inspircd.h"
#include "helperfuncs.h"
+#include "inspircd_config.h"
#include "socketengine.h"
#include "configreader.h"
+#ifdef THREADED_DNS
+pthread_mutex_t connmap_lock = PTHREAD_MUTEX_INITIALIZER;
+#endif
+
extern InspIRCd* ServerInstance;
extern ServerConfig* Config;
extern time_t TIME;
+extern userrec* fd_ref_table[MAX_DESCRIPTORS];
enum QueryType { DNS_QRY_A = 1, DNS_QRY_PTR = 12 };
enum QueryFlags1 { FLAGS1_MASK_RD = 0x01, FLAGS1_MASK_TC = 0x02, FLAGS1_MASK_AA = 0x04, FLAGS1_MASK_OPCODE = 0x78, FLAGS1_MASK_QR = 0x80 };
struct in_addr servers4[8];
int i4;
int initdone = 0;
-int wantclose = 0;
int lastcreate = -1;
class s_connection
ServerInstance->SE->DelFd(fd);
#endif
log(DEBUG,"DNS: dns_close on fd %d",fd);
- if (fd == lastcreate)
- {
- wantclose = 1;
- return;
- }
shutdown(fd,2);
close(fd);
return;
return NULL;
}
/* create new connection object, add to linked list */
+#ifdef THREADED_DNS
+ pthread_mutex_lock(&connmap_lock);
+#endif
if (connections.find(s->fd) == connections.end())
connections[s->fd] = s;
+#ifdef THREADED_DNS
+ pthread_mutex_unlock(&connmap_lock);
+#endif
- if (wantclose == 1)
- {
- shutdown(lastcreate,2);
- close(lastcreate);
- wantclose = 0;
- }
- lastcreate = s->fd;
return s;
}
*res = 0;
/* FireDNS used a linked list for this. How ugly (and slow). */
+
+#ifdef THREADED_DNS
+ /* XXX: STL really does NOT like being poked and prodded in more than
+ * one orifice by threaded apps. Make sure we remain nice to it, and
+ * lock a mutex around any access to the std::map.
+ */
+ pthread_mutex_lock(&connmap_lock);
+#endif
connlist_iter n_iter = connections.find(cfd);
if (n_iter == connections.end())
{
log(DEBUG,"DNS: got a response for a query we didnt send with fd=%d",cfd);
+#ifdef THREADED_DNS
+ pthread_mutex_unlock(&connmap_lock);
+#endif
return NULL;
}
else
/* We don't delete c here, because its done later when needed */
connections.erase(n_iter);
}
+#ifdef THREADED_DNS
+ pthread_mutex_unlock(&connmap_lock);
+#endif
l = recv(c->fd,buffer,sizeof(s_header),0);
dns_close(c->fd);
{
if (h.payload[i] > 63)
{
+ log(DEBUG,"DNS: h.payload[i] > 63");
memcpy(&p,&h.payload[i],2);
i = ntohs(p) - 0xC000 - 12;
}
if (ServerInstance && ServerInstance->stats)
ServerInstance->stats->statsDnsGood++;
dns_close(this->myfd);
+ this->myfd = -1;
return result;
}
else
if (this->myfd != -1)
{
dns_close(this->myfd);
+ this->myfd = -1;
}
return "";
}
if (this->myfd != -1)
{
dns_close(this->myfd);
+ this->myfd = -1;
}
if (result)
{
#ifdef THREADED_DNS
+
+/* This function is a thread function which can be thought of as a lightweight process
+ * to all you non-threaded people. In actuality its so much more, and pretty damn cool.
+ * With threaded dns enabled, each user which connects gets a thread attached to their
+ * user record when their DNS lookup starts. This function starts in parallel, and
+ * commences a blocking dns lookup. Because its a seperate thread, this occurs without
+ * actually blocking the main application. Once the dns lookup is completed, the thread
+ * checks if the user is still around by checking their fd against the reference table,
+ * and if they are, writes the hostname into the struct and terminates, after setting
+ * userrec::dns_done to true. Because this is multi-threaded it can make proper use of
+ * SMP setups (like the one i have here *grin*).
+ * This is in comparison to the non-threaded dns, which must monitor the thread sockets
+ * in a nonblocking fashion, consuming more resources to do so.
+ *
+ * NB: Yes this does scale, thank you. Even with large numbers of connecting clients
+ * in any one timeframe, they wont all connect *at the same time* therefore any argument
+ * of "but there will be thousands of threads it'll blow up" is moot, ive tested this and
+ * there will only ever be somewhere around the listen backlog in number of pending
+ * lookups at any one time. This is significant on any modern SMP system.
+ */
void* dns_task(void* arg)
{
userrec* u = (userrec*)arg;
+ int thisfd = u->fd;
+
log(DEBUG,"DNS thread for user %s",u->nick);
- DNS dns1;
- DNS dns2;
+ DNS dns1(Config->DNSServer);
+ DNS dns2(Config->DNSServer);
std::string host;
std::string ip;
- if (dns1.ReverseLookup((char*)inet_ntoa(u->ip4)))
+ int iterations = 0;
+
+ if (dns1.ReverseLookup(inet_ntoa(u->ip4),false))
{
- while (!dns1.HasResult())
- {
+ /* FIX: Dont make these infinite! */
+ while ((!dns1.HasResult()) && (++iterations < 20))
usleep(100);
- }
- host = dns1.GetResult();
- if (host != "")
+
+ if (iterations < 20)
{
- if (dns2.ForwardLookup(host), false)
+ if (dns1.GetFD() != -1)
{
- while (!dns2.HasResult())
+ host = dns1.GetResult();
+ if (host != "")
{
- usleep(100);
- }
- ip = dns2.GetResultIP();
- if (ip == std::string((char*)inet_ntoa(u->ip4)))
- {
- if (host.length() < 160)
+ if (dns2.ForwardLookup(host, false))
{
- strcpy(u->host,host.c_str());
- strcpy(u->dhost,host.c_str());
+ iterations = 0;
+ while ((!dns2.HasResult()) && (++iterations < 20))
+ usleep(100);
+
+ if (iterations < 20)
+ {
+ if (dns2.GetFD() != -1)
+ {
+ ip = dns2.GetResultIP();
+ if (ip == std::string(inet_ntoa(u->ip4)))
+ {
+ if (host.length() < 65)
+ {
+ if ((fd_ref_table[thisfd] == u) && (fd_ref_table[thisfd]))
+ {
+ if (!u->dns_done)
+ {
+ strcpy(u->host,host.c_str());
+ if ((fd_ref_table[thisfd] == u) && (fd_ref_table[thisfd]))
+ {
+ strcpy(u->dhost,host.c_str());
+ }
+ }
+ }
+ }
+ }
+ }
+ }
}
}
}
}
}
- u->dns_done = true;
+ if ((fd_ref_table[thisfd] == u) && (fd_ref_table[thisfd]))
+ u->dns_done = true;
+ log(DEBUG,"THREAD EXIT");
return NULL;
}
#endif
{
log(DEBUG,"Resolver::Resolver: RESOLVER_NSDOWN");
this->OnError(RESOLVER_NSDOWN);
+ ModuleException e("Resolver: Nameserver is down");
+ throw e;
+ /* We shouldnt get here really */
return;
}
{
log(DEBUG,"Resolver::Resolver: RESOLVER_NOTREADY");
this->OnError(RESOLVER_NOTREADY);
+ ModuleException e("Resolver: Core not initialized yet");
+ throw e;
+ /* We shouldnt get here really */
+ return;
}
}
projects / user / henk / code / inspircd.git / blobdiff